Resin substrate

ABSTRACT

A resin substrate is made of resin or a composite material containing resin. Pins each having the surface, on which Au plating is formed, are, with a soldering material made of Sn and Sb, soldered to a substrate body having a first main surface and formed into substantially a rectangular shape to project over the first main surface  2 A of the substrate body. Wettability of the soldering material for securing the pins and the substrate body to one another is relatively low as compared with that of a Pb—Sn soldering material. Therefore, the height of upward movement of the soldering material along the pin can be reduced. Hence it follows that the pins can sufficiently deeply be inserted into the socket so that the gap between the first main surface of the substrate body and the upper surface of the socket is reduced. As a result, the overall height realized after the substrate made of resin has been joined to the socket can be reduced

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a resin substrate, which has asubstrate body and a pin serving as an input/output terminal, and moreparticularly to a resin substrate having a pin which can reliably beconnected to a socket or another substrate.

[0003] 2. Description of the Related Art

[0004] Conventionally, a structure has been known in which a pin servingas an input/output terminal is secured and stood erect on a substratebody made of an insulating material, such as resin, for example, epoxyresin, or composite material of the resin and glass fibers, the pinbeing secured and stood erect by using a Pb—Sn soldering material, suchas Pb—Sn eutectic solder.

[0005] As the foregoing resin substrate, a resin substrate 101structured, for example, as shown in FIG. 6 is exemplified. A substratebody 102 of the resin substrate 101 has a resin insulating layer 103 anda circuit layer (not shown). A first main surface 102A of the resinsubstrate 101 has a connection pad 104 formed thereon. A solder resistlayer 105 is formed to reach the edge of the connection pad 104.

[0006] The pin 111 has a large-diameter portion 111A and a shaft portion111 b and having a structure that the overall surface is applied with Niplating or Au plating (not shown). The large-diameter portion 111A ofthe pin 111 is secured with a soldering material 115 to be opposite tothe connection pad 104 allowed to expose over the solder resist layer105. The soldering material 115 for establishing the connection betweenthe pin 111 and the substrate body 102 is welded to substantially theoverall surface of the exposed connection pad 104 and portions of thelarge-diameter portion 111A and the shaft portion 111 b such that thesoldering material 115 forms substantially a truncated-cone filletshape.

[0007] When the resin substrate 101 has been joined to the socket, alarge gap DSA is formed between the first main surface 102A of thesubstrate body 102 and the upper surface SKA of the socket SK, forexample, as shown in FIG. 7. When the resin substrate 101 is mounted onanother substrate or the like, also a large gap is formed. The reasonfor this lies in that the soldering material 115 upwards moved andwelded to the shaft portion 111 b of the pin 111 when the pin 111 issoldered to the substrate body 102 substantially enlarges the diameterof the shaft portion 111 b of the pin 111. Thus, the shaft portion 111Bcannot sufficiently deeply be inserted into the socket SK or a throughhole of the other substrate.

[0008] If the large gap is formed, the overall height realized after theresin substrate 101 has been joined to the socket SK or the like isenlarged excessively. Thus, a requirement for reducing the height cannotbe met. The pin 111 of a type which projects over the first main surface102A by a short length sometimes suffers from unsatisfactory reliabilityof the connection with the socket SK or the like. Moreover, arequirement for connecting the substrate made of the resin 101 and thesocket SK or the other substrate to each other for a shortest distancecannot be met.

[0009] As the wettability between the soldering material 115 and theAu-plated layer on the surface of the pin 111 is improved, the heightHSA of the soldering material 115 which upwards moves when the pin 111is secured is enlarged. When the wettability is adjusted to reduce theheight HSA of the soldering material 115 which upwards moves, it can beconsidered that the overall height realized after the resin substrate101 has been joined to the socket SK or the like can be reduced.

SUMMARY OF THE INVNETION

[0010] It is an object of the present invention to provide a resinsubstrate with which the gap between the substrate body and anothersubstrate or the like can be reduced when the resin substrate having amultiplicity of pins serving as input/output terminals and stood erectis joined to a socket or another substrate.

[0011] According to the present invention, there is provided a resinsubstrate, comprising: a substrate body made of resin or a compositematerial containing resin and formed into a plate-like shape which has afirst main surface; and a pin having a surface on which an Au-platedlayer is formed, wherein the pin is soldered to the substrate body witha soldering material mainly composed of Sn and Sb so as to be projectedover the first main surface of the substrate body.

[0012] The present invention has the structure that the solderingmaterial for securing the pin and the substrate body to each other isthe soldering material mainly composed of Sn and Sb. The foregoingsoldering material becomes wet with Au plating on the surface of thepin. The wettability is inferior to the Pb—Sn soldering material.Therefore, the foregoing soldering material, which is capable ofsoldering the pin to the substrate body, does not considerably upwardsmove along the pin.

[0013] Therefore, the portions to which the solder is welded and, thediameter of each of which is enlarged can be decreased. Hence it followsthat the pin can sufficiently deeply be inserted into the socket or thethrough hole of another substrate. Therefore, the gap between the firstmain surface of the substrate body and the socket or the other substratecan be reduced. As a result, the overall height realized after the resinsubstrate has been joined to the socket or the like can be reduced.

[0014] The substrate body may be made of resin, such as epoxy resin, oran insulating material made of a composite material of the foregoingresin and glass fibers. The substrate body includes a laminated circuitsubstrate having a core substrate, on either side or two sides of whichinsulating layers and circuit layers are alternately laminated. As analternative to this, a laminated circuit substrate having no coresubstrate and having the foregoing laminated structure is included.

[0015] The pin must have the surface on which the Au-plated layer isformed. The bonding strength of the substrate body or the like must beconsidered to arbitrary select the pin. The pin may be a pin in the formof the head of a nail or a pin having a large-diameter portion in anintermediate portion thereof. The material of the pin is exemplified bymetal, such as covar, a 42NI—Fe alloy or a copper alloy. It ispreferable that a Ni-plated layer is formed as the base layer for theAu-plated layer.

[0016] The soldering material must mainly be made of Sn and Sb. Inconsideration of the melting point and the bonding strength, thequantity of the foregoing elements must be determined. In addition tothe elements, such as Sn and Sb, Ag, Bi, Au, Pb, In, Al, As or the likemay be added in a small quantity.

[0017] In the present invention, it is preferable that the height of thepin projecting over the first main surface is 2 mm or smaller.

[0018] If the length of the pin projecting over the first main surfaceof the substrate body is too short, that is, if the length is 2 mm orsmaller, the portion of the pin which can be inserted into the socket orthe through hole of the substrate is too short to reliably connect theresin substrate to the socket or the like when upward movement of thesoldering material takes place greatly. If the connector of the socketis brought into contact with the soldering material which covers thepin, the reliability of the connection sometimes deteriorates ascompared with the reliability realized when the contact with theAu-plated layer is made.

[0019] The present invention, which is arranged to use the solderingmaterial mainly composed of Sn and Sb having a poor wettability with thepin as compared with the Pb—Sn soldering material, is able to preventupward movement of the soldering material which occurs when the pin issecured. Although the portion of the pin which projects over thesubstrate body is short, a sufficiently long portion of the pin which isinserted into the socket or the through hole of the other substrate canbe maintained. As a result, the resin substrate can reliably beconnected to another substrate or the like.

[0020] In the present invention, it is preferable that the thickness ofthe Au-plate layer of the pin is 0.04 m or larger.

[0021] If the thickness of the Au-plated layer on the surface of the pinis enlarged, the soldering material is easily wetted. Thus, the heightrealized by the upward movement is enlarged. Therefore, when a solderingmaterial, such as a Pb—Sn soldering material, having considerablewettability is used, the thickness of the Au-plated layer cannot beenlarged.

[0022] On the other hand, the present invention arranged to use theSn—Sb soldering material and having poor wettability is able to preventupward movement if the Au-plated layer having a large thickness isformed. Therefore, the Au-plated layer having a large thickness of 0.04μm or larger, for example, 0.05 μm or 0.1 μm, can be formed to maintainthe antioxidation characteristic and reliability of the connection withthe socket or the like.

[0023] In the present invention, it is preferable that the quantity ofSb contained in the soldering material is 15 wt % or lower.

[0024] If the melting point of the strength material is too high, theoperation for soldering the pin to the substrate body sometimesencounters deterioration in the characteristics of the substrate body,in particular, the resin insulating layer, at the soldering temperatureaccording to the material. Moreover, the substrate body is sometimesdecolored.

[0025] According to the present invention, the soldering material ismainly composed of Sn and Sb and arranged to contain Sb by 15 wt % orsmaller. Therefore, the melting point of the soldering material is 280°C. or lower. Hence it follows that the pin can be soldered to thesubstrate body at a low soldering temperature. As a result, a materialhaving excellent heat resistance is not required when the solderingoperation is performed. Thus, reliable connection can be performedwithout any deterioration in the characteristics of the substrate body.Moreover, decoloration of the substrate body can be prevented orrestrained. Since wettability required to secure the pin and thesubstrate body to each other can sufficiently be maintained, thereliability of the connection between the pin and the substrate body canbe improved.

[0026] In the present invention, it is preferable that the quantity ofSb contained in the soldering material is not less than 3 wt % nor morethan 15 wt %.

[0027] When the quantity of Sb contained in the Sn—Sb soldering materialis 3 wt % or larger, deterioration in the wettability of the solderingmaterial apparently occurs. Therefore, when the quantity of contained Sbis 3 wt % or larger, upward movement of the soldering material whichtakes place when the pin is secured can reliably be prevented. Hence itfollows that manufacturing yield of the resin substrate can furthermorebe improved.

[0028] In the present invention, it is preferable that the melting pointof the soldering material is 280° C. or lower.

[0029] As described above, if the melting point of the strength materialis too high, the operation for soldering the pin to the substrate bodysometimes encounters deterioration in the characteristics of thesubstrate body, in particular, the resin insulating layer, at thesoldering temperature according to the material. Moreover, the substratebody is sometimes decolored.

[0030] Since the present invention is structured such that the meltingpoint of the soldering material is 280° C. or lower, a material havingexcellent heat resistance is not required when the pin is secured toprevent or restrain deterioration in the characteristics of thesubstrate body.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In the accompanying drawings:

[0032]FIG. 1 is a partially-enlarged cross sectional view showing aresin substrate according to embodiments 1 to 3;

[0033]FIG. 2 is a partially-enlarged cross sectional view showing astate in which the resin substrate according to embodiments 1 to 3 hasbeen joined to a socket;

[0034]FIGS. 3A to 3C are diagrams showing a method of manufacturing theresin substrate according to embodiments 1 to 3, FIG. 3A showing thesubstrate body, FIG. 3B showing a state in which a solder ball has beenplaced on the substrate body and FIG. 3C showing a state in which thepin has been secured to the substrate body;

[0035]FIG. 4 is a partially-enlarged cross sectional view showing aresin substrate according to embodiments 4 to 6;

[0036]FIG. 5 is a partially-enlarged cross sectional view showing astate in which the resin substrate according to embodiments 4 to 6 hasbeen joined to the other substrate;

[0037]FIG. 6 is a partially-enlarged cross sectional view showing aconventional substrate; and

[0038]FIG. 7 is a partially-enlarged cross sectional view showing astate in which the conventional substrate has been joined to a socket.

PREFERRED EMBODIMENTS OF THE INVENTION

[0039] (Embodiments 1, 2 and 3)

[0040] Preferred embodiments of the present invention will now bedescribed with reference to the drawings.

[0041] A resin substrate according to the present invention is shown inFIG. 1 which is a partially-enlarged cross sectional view.

[0042] The substrate 1 made of resin has a substrate body 2 formed intosubstantially a rectangular shape having size of 32 mm×36 mm and athickness of 1 mm. A first main surface 2A of the substrate body 2 has anail-head-shape pins 11 serving as input/output terminals stood erect toform a lattice configuration by using a soldering material 15 made ofSn—Sb. Embodiments 1, 2 and 3 have the same structure except for thedifferent soldering materials 15. Embodiment 1 is arranged to use asoldering material (having a melting point of 240° C.) made of 95Sn—5Sb,embodiment 2 is arranged to use a soldering material (having a meltingpoint of 235° C.) made of 98Sn—2Sb and embodiment 3 is arranged to use asoldering material (having a melting point of 315° C.) made of80Sn—20Sb.

[0043] The substrate body 2 has a resin insulating layer 3 made of epoxyresin and a circuit layer (not shown) made of copper. The first mainsurface 2A has a connection pad 4 made of copper. An opening 6 (having adiameter of 0.65 mm) is formed to reach the edge of the connection pad4. Moreover, a solder resist layer 5 (having a thickness of 20 μm) madeof epoxy resin is formed.

[0044] On the other hand, the pin is made of covar and having anail-head-shape large-diameter portion 11A (having a diameter of 0.6 mmand a height of 0.1 mm) and a shaft portion 11B (having a diameter of0.38 mm and a height (a length) of 0.95 mm). A Ni—P plated layer 12having a thickness of 2 μM is formed on the overall surface of the pin11. Moreover, an Au-plated layer 13 having a thickness of 0.05 μm isformed on the surface of the Ni—P plating layer 12. When a manufacturingprocess is performed, contact of the soldering material 15 with theAu-plated layer 13 causes the Au plating 13 to be dissolved anddispersed in the soldering material 15. Therefore, the solderingmaterial 15 is welded to the Ni—P plating 12 in the portions of thesurface of the pin 11 to which the soldering material 15 has beenwelded.

[0045] The substrate body 2 and the pin 11 are secured to each otherwith the soldering material 15 such that the large-diameter portion 11Aof the pin 11 is positioned opposite to the connection pad 4 exposed tothe outside over the solder resist layer 5 of the substrate body 2. Theheight PS of projection of the pin 11 when viewed from the first mainsurface is 1 mm. The soldering material 15 is welded to substantiallythe overall surface of the exposed connection pad 4, the overall body ofan engaging portion 11A of the pin 11 and a portion (an upper portion inthe drawing) of the shaft portion 11B such that a moderate circulartruncated cone fillet shape is formed. The height HS of upward movementof the welded soldering material 15 over the connection pad 4 is 0.25 mmin embodiment 1, 0.35 mm in embodiment 2 and 0.06 mm in embodiment 3.

[0046]FIG. 2 is a partially-enlarged cross sectional view showing astate in which the substrate 1 made of resin has been joined to a socketST.

[0047] The socket ST has an upper surface STA in which a multiplicity ofblind holes BL are formed at positions corresponding to the positions ofthe pins 11 of the substrate 1 made of resin. Moreover, the socket SThas contacts SSA for securing the shaft portions 11B of the pins 11inserted into the blind holes BL; and terminals SSB molded integrallywith the contacts SSA and allowed to project over a lower surface STB ofthe socket.

[0048] The terminals SSB projecting over the lower surface STB of thesocket ST are inserted into through via conductors of another substrateWT so as to be secured by using a soldering material HD.

[0049] The height HS of upward movement of the soldering material 15,the appearance of the substrate 1 made of resin and the like wereexamined as follows.

[0050] The height HS of upward movement of the soldering material 15 ofthe substrate 1 made of resin according to each of embodiments 1, 2 and3 was measured. Thus, average values of five samples were obtained.Moreover, the appearance of the resin substrate 1 to which the pins 11have been soldered was inspected. As comparative examples, substratesmade of resin which were the same as those according to the embodimentexcept for the soldering materials were manufactured. Then, the heightHS of upward movement and the appearance were similarly measured andinspected.

[0051] Results of measurement were collectively shown in Table 1. TABLE1 Point of Temperature Soldering of Soldering Compo- HS MaterialMaterial nent (mm) (° C.) (° C.) Appearance Embodiment 95Sn5Sb 0.25 240250 satisfactory 1 Embodiment 98Sn2Sb 0.35 235 245 satisfactory 2Embodiment 80Sn20Sb 0.06 315 325 deteriorated 3 Comparative 37Pb63Sn0.84 183 210 satisfactory Example 1 Comparative 50Pb50Sn 0.74 226 236satisfactory Example 2

[0052] As can be understood from Table 1, the height HS of upwardmovement of the soldering material 15 which was Sn—Sb soldering materialaccording to embodiments 1, 2 and 3 was 0.25 mm in embodiment 1, 0.35 mmin embodiment 2 and 0.06 mm in embodiment 3. As compared withcomparative examples (0.84 mm in Comparative Example 1 and 0.74 mm inComparative Example 2) arranged to use the Pb—Sn soldering material, theheight HS of upward movement was reduced. In particular, embodiments 1and 3 containing Sb by 3 wt % or larger were able to reduce the heightHS of upward movement of the soldering material 15.

[0053] On the other hand, Comparative Examples 1 and 2 arranged to usethe Pb—Sn soldering material encountered a fact that a major portion ofprojection of each pin was wetted with the solder. Therefore, the lengthof each pin which can be inserted into the socket is insufficientlyshort. Hence it follows that the resin substrate cannot reliably bejoined to the socket.

[0054] Note that embodiment 3 encountered a fact that the substrate bodywas partially decolored and the insulating layer deteriorated. Thesubstrates made of resin except for embodiment 3 has the structures thatthe melting point of the soldering material is 240° C. in embodiment 1,235° C. in embodiment 2, 183° C. in Comparative Example 1 and 226° C. inComparative Example 2. The foregoing temperatures were relatively lowtemperatures which were 280° C. or lower. Also the solderingtemperatures are somewhat higher than the melting points by about 10° C.On the other hand, embodiment 3 is arranged to use the solderingmaterial having the melting point which is 315° C. and arranged toperform soldering at 325° C. Thus, the temperatures are high asdescribed above. When a substrate body made of a material, such aspolyimide, having excellent heat resistance is employed, decoloration ofthe substrate body and deterioration in the insulating layer do notoccur if the soldering material (80Sn—20Sb) according to embodiment 3 isemployed.

[0055] As described above, the substrate 1 made of resin according toembodiments 1, 2 and 3 has the structure that the soldering material 15for securing the pins 11 and the substrate body 2 is made of Sn—Sb.Therefore, low wettability can be realized as compared with the Pb—Snsoldering material. Therefore, the height HS of upward movement of thesoldering material 15 can be reduced. In particular, the quantity ofcontained Sb is 3 wt % or larger such that the quantity is 5 wt % inembodiment 1 and 20 wt % in embodiment 3. Therefore, the height HS ofupward movement of the soldering material can furthermore be reduced.

[0056] Therefore, the pins 11 can sufficiently deeply be inserted intothe socket ST. Thus, gap DS between the first main surface 2A of thesubstrate body 2 and the upper surface STA of the socket ST can bereduced. Therefore, the overall height realized after the substrate 1made of resin has been joined to the socket ST can be reduced.

[0057] The length (projection length) PS of the pin 11 projecting overthe first main surface 2A is a short length of 1 mm. However, also theheight HS of upward movement of the soldering material 15 is reducedsuch that the HS is 0.25 mm in embodiments 1, 0.35 mm in embodiments 2and 0.6 mm in embodiments 3. Therefore, the diameter of the shaftportion 11B can be enlarged, causing the portion which cannot beinserted into the socket ST to be reduced. As a result, the substrate 1made of resin can reliably be connected to the socket ST.

[0058] Since the Au-plated layer 13 formed on the surface of the pin 11has a large thickness of 0.05 μm, the antioxidation characteristic andreliability of the connection with the socket ST (the contact SSA) canbe improved.

[0059] The quantity of Sb contained in the soldering material 15 is 15wt % or smaller such that the quantity was 5 wt % in embodiment 1 and 2wt % in embodiment 2. Moreover, the melting point of the solderingmaterial 15 is 280° C. or lower such that the melting point was 240° C.in embodiment 1 and 235° C. in embodiment 2. Therefore, a materialhaving excellent heat resistance is not required to prevent decolorationof the resin insulating layer 3 and the solder resist layer 5 anddeterioration in the insulating characteristic when soldering isperformed.

[0060] A method of manufacturing the substrate 1 made of resin will nowbe described with reference to FIGS. 3A to 3C.

[0061] Initially, the substrate body 2 shown in FIG. 3A is manufactured.That is, a known method is employed to form the resin insulating layer3. Then, the solder resist layer 5 is formed such that the connectionpad 4 is exposed over the first main surface 2A.

[0062] Then, as shown in FIG. 3B, a solder ball 15A made of Sn—Sbsoldering material (95Sn—5Sb in embodiment 1, 98Sn—2Sb in embodiment 2and 80Sn—20Sb in embodiment 3) is placed on the connection pad 4 of thefirst main surface 2A. Moreover, the pin 11 applied with the Ni—Pplating 12 and the Au plating 13 is prepared. Then, the solder ball 15Ais heated and melted at a temperature higher than the melting point ofthe soldering material by about 10° C. for one minute. As shown in FIG.3C, portions of the large-diameter portion 11A and the shaft portion 11Bof the pin 11 adjacent to the connection pad 4 are secured to thesubstrate body 2. Thus, the substrate 1 made of resin according to thisembodiment is manufactured.

[0063] The soldering material 15 is wetted by the shaft portion 11B ofthe pin 11 which is applied with the Au plating 13 so as to be formedinto a moderate fillet shape having a relatively low height HS of upwardmovement. The Au-plated layer 13 made contact with the solderingmaterial 15 is melted and dispersed in the soldering material 15 in avery short time. Therefore, the soldering material 15 is welded to theNi—P-plated layer 12 of the pin 11, as shown in FIG. 1.

[0064] (Embodiments 4, 5 and 6)

[0065] Embodiments 4, 5 and 6 will now be described with reference toFIG. 4. A substrate 21 made of resin according to embodiments 4, 5 and 6is different from embodiments 1, 2 and 3 in that a nail-head-shape pin31 penetrates the substrate body 22 from the second main surface 22B tothe first main surface 22A. The other structures are the same asembodiments 1, 2 and 3. Therefore, similar portions to those ofembodiments 1, 2 and 3 are omitted from description or described simply.

[0066] The substrate 21 made of resin has a substrate body 22 formedinto substantially a rectangular shape and having a multiplicity ofnail-head-shape pins 31 in the lattice-like configuration by using asoldering material 35 made of Sn—Sb. Embodiments 4, 5 and 6 aredifferent from one another in only the soldering materials 35. The otherportions are the same. A soldering material (having a melting point of240° C.) made of 95Sn—5Sb is employed in embodiment 4, a solderingmaterial (having a melting point of 235° C.) made of 98Sn—2Sb isemployed in embodiment 5 and a soldering material (having a meltingpoint of 315° C.) made of 80Sn—20Sb is employed in embodiment 6.

[0067] The substrate body 22 has a resin insulating layer 23 and solderresist layers 25 and 29. The resin insulating layer 23 has a throughhole 36 formed from the lower surface 23A to the upper surface 23B.Moreover, a through via conductor 37 is formed in the inner wall of thethrough hole 36. A first connection pad 24 is formed around the throughhole 36 at a position on the lower surface 23A. A solder resist layer 25having an opening 26 is formed to reach the first connection pad 24. Onthe other hand, a circuit layer 27 is provided for the upper surface23B. A solder resist layer 29 having an opening 30 is formed in theportion of the second connection pad 28 formed around the through hole36.

[0068] On the other hand, the pin 31 is made of covar and having anail-head-shape large-diameter portion 31A (having a diameter of 0.6 mmand a height of 0.1 mm) and a shaft portion 31B (having a diameter of0.38 mm and a height (a length) of 2 mm. A Ni—P-plated layer 32 having athickness of 2 μm is formed on the overall surface of the pin 31.Moreover, an Au-plated layer 33 having a thickness of 0.05 μm is formedon the Ni—P-plated layer 32. Similarly to embodiments 1, 2 and 3,portions of the surface of the pin 31 to which the soldering material 35has been welded are welded to the Ni—P-plated layer 32.

[0069] The pin 31 is soldered while the large-diameter portion 31A isbeing engaged to the second connection pad 28. The shaft portion 31Bpenetrates the through via conductor 37 to project downwards over thefirst main surface 22A so as to be soldered to the through via conductor37 and the first connection pad 24. Thus, the pins 31 are secured to thesubstrate body 22. The portion of the soldering material 35 welded tothe portion of the first connection pad 24 and the shaft portion 31B ofthe pin 31 is formed into a moderate fillet shape in the form of acircular truncated cone shape. The height HS of upward movement of thewelded soldering material 35 over the first connection pad 24 is 0.22 mmin embodiment 4, 0.33 mm in embodiment 5, and 0.05 mm in embodiment 6.Note that the height PS of projection of the pin 31 over the first mainsurface 22A is 1 mm.

[0070]FIG. 5 is a partially enlarged cross sectional view showing astate in which the substrate 21 made of resin has been joined to anothersubstrate WB. The substrate WB has a multiplicity of through holes THcorresponding to the positions of the pins 31 of the substrate 21 madeof resin. A cylindrical conductor layer TD having a through hole TDH isformed in the inner wall of the through holes TH and around the throughholes TH of the upper and lower main surfaces WBA and WBB. A portion ofthe shaft portion 31B of the pin 31 is inserted into the through holeTDH of the other substrate WB so as to be soldered. Thus, the substrate21 made of resin is connected to the other substrate WB.

[0071] The height HS of upward movement of the soldering material 35,the appearance of the substrate 21 made of resin and the like wereexamined as follows.

[0072] The height HS of upward movement of the soldering material 35 ofthe substrates 21 made of resin according to embodiments 4, 5 and 6having the structures that the compositions of the soldering materials35 were different from one another was measured. An average value offive samples was obtained. Also the appearance of the substrate 21 madeof resin was inspected. As comparative examples, substrates made ofresin were manufactured which were the same as those according toembodiments 4, 5 and 6 except for the soldering materials to performsimilar measurement and inspection.

[0073] Results of the measurement were shown in Table 2. TABLE 2 MeltingTemper- Point of ature of Soldering Soldering HS Material MaterialComponent (mm) (° C.) (° C.) Appearance Embodiment 95Sn5Sb 0.22 240 250satisfactory 4 Embodiment 98Sn2Sb 0.33 235 245 satisfactory 5 Embodiment80Sn20Sb 0.05 315 325 deteriorated 6 Comparative 37Pb63Sn 0.81 183 210satisfactory Example 3 Comparative 50Pb50Sn 0.70 226 236 satisfactoryExample 4

[0074] As can be understood from Table 2, similarly to the foregoinginspection, the resin substrate (according to embodiments 4, 5 and 6)arranged to use the Sn—Sb soldering material is able to reduce theheight HS of upward movement of the soldering material as compared withComparative Examples 3 and 4 arranged to use the Pb—Sn solderingmaterial. In particular, embodiments 4 and 6 arranged to contain Sb by 3wt % or larger are able to reduce the height HS of upward movement ofthe soldering material.

[0075] On the other hand, Comparative Examples 3 and 4 arranged to usethe Pb—Sn soldering material encounter wetting of a major portion ofprojection of the pin with the solder. Therefore, the shaft portion ofthe present invention cannot sufficiently deeply be inserted into thethrough hole TDH of the other substrate WB.

[0076] Note that embodiment 6 encountered a fact that the substrate bodywas partially decolored and the insulating layer deteriorated. Similarlyto the foregoing inspection, the substrates made of resin except forembodiment 6 has the structures that the melting point of the solderingmaterial is a relatively low temperature of 280° C. or lower. Also thesoldering temperatures are somewhat higher than the melting points byabout 10° C. On the other hand, embodiment 6 is arranged to use thesoldering material having the melting point which is 315° C. andarranged to perform soldering at 325° C. Thus, the temperatures are highas described above. When a substrate body made of a material, such aspolyimide, having excellent heat resistance was employed, decolorationof the substrate body and deterioration in the insulating layer did notoccur when the soldering material according to embodiment 6 wasemployed, similarly to embodiment 3.

[0077] As described above, the substrate 21 made of resin according toembodiments 4, 5 and 6 has the structure that the soldering material 35for securing the pins 31 and the substrate body 22 is made of Sn—Sb.Therefore, low wettability can be realized as compared with the Pb—Snsoldering material. Therefore, the height HS of upward movement can bereduced. It leads to a fact that the shaft portion 31B of the pin 31 cansufficiently deeply be inserted into the through hole TDH. Thus, gap TSbetween the first main surface 22A of the substrate body 22 and theupper surface WBA of the other substrate WB can be reduced. Therefore,the overall height realized after the substrate 21 made of resin hasbeen connected to the other substrate WB can be reduced.

[0078] The projection height PS of the pin 31 is a short length of 1 mm.However, also the height of upward movement of the soldering material 15is reduced. Therefore, the portion of the shaft portion 11B, thediameter of which is enlarged, is decreased. Thus, the pin can deeply beinserted into the through hole TDH of the other substrate WB so thatreliable connection is established.

[0079] Since the Au-plated layer 33 formed on the surface of the pin 31has a large thickness of 0.05 μm, the antioxidation characteristic andreliability of the connection with the other substrate WB can beimproved.

[0080] Moreover, the melting point of the soldering material 35according to embodiments 4 and 5 is relatively low. Therefore, amaterial having excellent heat resistance is not required to preventdecoloration of the resin insulating layer 23 and the solder resistlayer 25 and deterioration in the insulating characteristic whensoldering is performed at a high temperature.

[0081] The substrate 21 made of resin according to this embodiment ismanufactured such that the substrate body 22 is manufactured by a knownmethod. Then, an annular solder preform made of the Sn—Sb solderingmaterial 35 (95Sn—5Sb in embodiment 4, 98Sn—2Sb in embodiment 5 and80Sn—20Sb in embodiment 6) is placed on the second connection pad 28 ofthe first main surface 22A of the substrate body 22. Then, the pins wereinserted, and then the soldering material 35 is heated at a temperaturewhich is higher than the melting point by about 10° C. for one minute.Thus, the pins 31 are secured to the substrate body 22 so that thesubstrate 21 made of resin is manufactured.

[0082] The embodiments of the present invention have been described. Thepresent invention is not limited to the description of the embodiments.As a matter of course, arbitrary modifications may be performed withinthe scope of the spirit of the present invention.

[0083] For example, embodiments 1, 2 and 3 have the structure that thesubstrate 1 made of resin is joined to the socket ST. In embodiments 4,5 and 6, the substrate 21 made of resin is joined to the other substrateWB. The substrate 1 made of resin according to embodiments 1 and thelike may be joined to the other substrate or the substrate 21 made ofresin according to embodiments 4 and the like may be joined to thesocket. The length of each of the shaft portions 11B and 31B of the pins11 and 31 may arbitrarily be adjusted. In any case, the height HS ofupward movement of the soldering materials 15 and 35 can be reduced.Therefore, the gap between each of the substrate bodies 2 and 22 and theother substrate or the socket can be reduced.

What is claimed is:
 1. A resin substrate comprising: a substrate bodymade of resin or a composite material containing resin and formed into aplate-like shape which has a first main surface; and a pin having asurface on which an Au-plated layer is formed; wherein said pin issoldered to said substrate body with a soldering material comprising Snand Sb so as to be projected over said first main surface of saidsubstrate body.
 2. The resin substrate according to claim 1, wherein theheight of said pin projecting over said first main surface is 2 mm orsmaller.
 3. The resin substrate according to claim 2, wherein thethickness of said Au-plated layer of said pin is 0.04 μm or larger. 4.The resin substrate according to claim 2, wherein the quantity of Sbcontained in said soldering material is 15 wt % or smaller.
 5. The resinsubstrate according to claim 3, wherein the quantity of Sb contained insaid soldering material is 15 wt % or smaller.
 6. The resin substrateaccording to claim 2, wherein said soldering material has a meltingpoint of 280° C. or lower.
 7. The resin substrate according to claim 3,wherein said soldering material has a melting point of 280° C. or lower.8. The resin substrate according to claim 1, wherein said solderingmaterial further comprises at least one of Ag, Bi, Au, Pb, In, Al, As.